1. Field of the Invention
One aspect of the present invention relates to fluid handling and more specifically to faucets. Another aspect relates to automatic temperature regulation and more specifically to a device operated by a thermostat located in the fluid that is controlled, so that its own temperature controls its flow. In a further aspect, the invention relates to an electrically actuated valve. An electronic faucet is automatically controlled by object detection circuitry so that a user can start water flow through the faucet without any physical contact. The water faucet has touchless water temperature and flow adjustment
2. Description of Prior Art
Electronic faucets are often located in public restrooms such as at airports or restaurants or at commercial washstands in medical institutions where it is important to maintain hygiene. These locations tend to be public rather than residential. In a largely public setting a faucet must operate in an intuitive manner since the user has no reliable means of learning detailed methods of operation. In typical operation, active infrared detectors in the form of photodiode pairs are used for various methods and in various locations for infrared detection of objects.
Faucets in public locations might perform the singular and relatively simple task of touchless “on” and “off” operation. Further, different brands of electronic faucets each will operate according to the different manufacturer's preferences, resulting in a lack of uniformity over control of any unusual abilities incorporated into such differently branded faucets. Consequently, in many public or commercial settings, the user knows only to place his hands near or below an electronic faucet and to hope he triggers a sensor that causes the faucet to operate in response.
Despite the practical inability to educate users of public faucets in more than fundamental operations, manufacturers have improved the operation and reliability of electronic faucets while maintaining simple, intuitive methods of control. Many electronic faucets employ infrared sensors for user input, because such sensors can detect the presence of the user, the presence of the user's hands below the faucet, or the presence of another object below the faucet. However, infrared sensors can malfunction due to the presence of unintended infrared sources. Various solutions anticipate the presence of changing infrared input levels. For example, U.S. Pat. No. 6,202,980 to Vincent et al. describes a sensor with a calibrated setpoint that automatically adjusts to follow changing infrared levels, only triggering the faucet when the level changes by too much to be accommodated by the normal tracking routine. The faucet avoids inadvertent operation, although the user is able to operate the faucet by the usual intuitive steps.
In addition to improved flow control, an electronic faucet can offer improved temperature control without requiring additional user training. For example, U.S. Pat. No. 5,577,660 to Hansen describes a system with multiple sensors communicating with a controller that compensates for lag time of hot water arriving from a hot water supply. As another example, U.S. Pat. No. 5,625,908 to Shaw describes a fully automated wash station that responds to the basic infrared sensor of the type that typically initiates water flow; but in this scheme the single actuation of that sensor also initiates automatic enhancements including the automated dispensing soap with the water stream for hand washing and the automated dispensing of a length of towel for drying the hands. By an alternate method of triggering the sensor, a knowledgeable user can cancel the enhanced functions to thereby obtain only potable water for drinking without the included soap ration and towel. Thus, the Shaw faucet accommodates users of increased knowledge by offering a simplified function, although the fundamental triggering of water flow together with the associated enhancements remains at the intuitive level to serve those users who are not informed of the alternate operational method.
The home environment offers the greatest challenge to the use of an automatic, electronic faucet. Commercial restrooms or wash stations typically offer a static environment in terms of ambient light conditions, while a home kitchen can be a dynamic environment where light source and intensity vary throughout the day, encompassing sunlight, fluorescent light, and incandescent light. U.S. Pat. No. 5,549,273 to Aharon proposed a kitchen-style faucet operated by a microprocessor and various sensors that could learn surrounding light conditions and adapt the threshold value for faucet actuation to the surrounding conditions. In addition, Aharon proposed two operational modes of water flow. In one mode, the flow operated in the basic “on” and “off” mode according to whether the sensors detected an object, while in a second mode the flow would remain on until signaled to stop. The latter mode was considered desirable for washing dishes.
A home user is more likely to desire and use an expanded feature set. A home user is likely to demand control over kitchen faucet water temperatures, flow rates and spray patterns, in addition to simple “on” and “off” operation or even an expanded “on” cycle. In-home users of kitchen faucets also have a general expectation of how such faucets should operate. The ability to swivel a kitchen faucet around a kitchen sink is a basic expectation. An automatic faucet requires greatly expanded sophistication to simply pivot over a typical double well sink basin without falsely being activated over the sink dam and, even worse, over the countertop behind the basin. False touchless temperature adjustments would occur simply when moving the faucet spout to a different location over the sink.
Some basic needs of a kitchen faucet have been addressed. The present inventors addressed the problem of a pivoting electronic faucet as described in U.S. Pat. No. 4,762,273 to Gregory et al., in which faucet positions are defined with respect to the faucet base. The angular positions that the spout can assume are identified as various zones. The zones are programmed to be active or non-active. Thus, a countertop could be in a non-active zone. According to the further U.S. Pat. No. 4,735,357 to Gregory et al., if the spout is turned by a preset angle to the side, the water flow is forced off for maintenance.
Several patents have proposed additional improvement in controlling flow and temperature in kitchen faucets. U.S. Reissue Pat. No. RE37,888 to Cretu-Petra proposes the use of two separate proximity sensors to individually control flow and temperature. The respective sensors detect a distance to the user's hands and adjust flow and temperature accordingly. In addition, Cretu-Petra proposes that a speaker and microphone might be incorporated into a faucet to allow oral commands controlling flow and temperature and to allow the faucet to issue oral status reports. Another disclosed feature is an electrode system enabling automatic filling of a washbasin and automatically shutting off water to prevent overflow. U.S. Pat. No. 6,513,787 to Jeromson et al. proposes the use of two related hand detecting sensors on opposite sides of a faucet, with the sensor on one side initiating an increase in water temperature and the sensor on the opposite side initiating a decrease in water temperature. A display of light emitting diodes (LEDs) on the faucet informs the user of the selected temperature.
Although such basic matters as temperature and flow have been controlled electronically, the promise of enhanced functionality by electronic control of a kitchen faucet remains substantially unrealized. As demonstrated in the above patents, a modern electronic faucet might offer the advantage of touchless operation, but this is only the most basic feature that electronics might offer. Few additional features are known. Touchless electronic temperature control, touchless electronic flow control, and swivel ability in a touchless faucet have presented technical challenges and limited solutions have been proposed. However, in mechanical faucets these features are well established, reliable, and so thoroughly expected that a homeowner is likely to reject any kitchen faucet that lacks such features, whether electronic or not.
For an electronic faucet to compete successfully with standard mechanical designs, it is evident that the electronic faucet must offer benefits both matching and exceeding those of typical mechanical faucets. The difficulty in expanding the electronic feature set includes development of sensible, easily learned operating methods. Some electronic faucets have resorted to a combination with manual mechanical control over certain standard features. As an example found in the Gregory U.S. Pat. No. 4,735,357, a manually actuated lever controls a spray wash through a conventional diverter valve. While it is commendable to incorporate standard and expected features in an electronic faucet, resort to manual levers adds little to recommend the electronic faucet over the prior mechanical designs and should be used with care and discretion.
In order for an electronic faucet to achieve success, it would be desirable to expand the scope and quality of touchless controls, as well as to provide an improved, real time technique for educating the user in methods of operating the faucet. Such known concepts as controlling flow pattern for swivel spout faucets, regulating flow rate, and setting temperature can be improved. Likewise, electronic faucets can be improved in the area of new functions that would be difficult to achieve in a purely mechanical faucet. In the area of controls, it would be a significant improvement to activate or deactivate manual and electronic controls as a function of real time faucet configuration so as to enhance the user's overall experience in operating the faucet. Altering the function of different controls can be especially effective in circumstances where the user must otherwise grasp a manual control or the faucet part carrying the manual control as an adjunct step to using a feature of the faucet.
It would be desirable to develop manual and electronic control schemes for converting known, purely manual systems, such as a spray wash, to a system operated with enhanced characteristics. Developing intuitive operational controls, or suitably instructing the user in real time, would be significant enabling achievements.
It would be further desirable to develop operational controls and methods capable of producing new and useful functions in a faucet. It would be especially desirable to introduce new functionality that benefits from electronic control, while being less suited to implementation by manual control.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, the method and apparatus of this invention may comprise the following.